Dust insecticide and method and apparatus for making the same



at. M mm wlmm H. m. MOCONNELL DUST INSECTICIDE AND METHOD AND APPARATUS FOR MAKING THE SAME Filed Aug. 5, 1922 Ezyz.

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ENRY K. MCCONNELL, OF RICHMOND, VIRGINIA, ASSIGNOR TO TOBAGCO-BY-PROD- UCTS AND CHEMICAL CORPORATION, OF LOUISVILLE, KENTUCKY, A CORPORA- rron or DELAW.

DUST INSEGTICIJDE AND METHOD AND APPARATUS FOR MAKING- THE SE.

Application filed August 5, 1922. erial No. 579,852.

To all whom it may concern Be it known that I, HENRY K. MCCON- NELL, a citizen of the United States, residing at Richmond, county of Henrico, and 5 State of Virginia, have invented certain new and useful Improvements in Dust Insecticides and Methods and Apparatus for Making the Same, fully described and represented in the following specification and W the accompanying drawings, forming a part of the same.

This invention relates to improvements in dust insecticides, and to a new and improved process of making the same, as well as to a W new apparatus for carrying out the process.

It has been recognized within recent times that an insecticide which has properties such that it can be dusted onto plants is more advantageous for some purposes than a liquid insecticide which must be sprayed onto the plants.

On the other hand, it has also been recognized for a long time that forv certain insects an insecticide containing nicotine in proper quantities must be employed. Up to the present time, however, there has not been produced a satisfactory dust insecticide containing nicotine in such a form and so thoroughly distributed throughout all parts of the dust as to constitute a reliable and economical insecticide. 7

It is the object .of the present invention to provide a dust insecticide comprising a finely powdered or dust-like carrier of ma- Wi terial which is inert or inactive to nicotine or its compounds, substantially every par: ticle of such carrier being coated with free nicotine or a nicotine compound, the' amount of such coating being substantially prop'orll tional to the surfaces of the carrier particles. There have been produced heretofore dust insecticides carrying nicotine salts, but owing to' the method of production employed, the nicotinesalts were not distributed M uniformly over the surfaces of the particles. 0n the contrary, the dust particles of larger size carried the largest proportion of nicotine salt and the smallest particles carried the smallest proportion. Hence, with these prior dust insecticides, if the product were sifted so as to grade the material into grades of different degrees of fineness, and separate analyses of the separate grades were made,

it would be found that the percentage of nicotine salt increased with the coarseness, or, conversely, the finer grades carried the lesser percent-age of nicotine salt.

My new product is distinguished from these old products by the fact that upon sifting the dust to form' a plurality of grades of different degrees of fineness, an analysis-of samples from the difierent grades will show that the percentage of nicotine increases with the fineness and in a general way is substantially proportional to the surfaces of the particles, that is, the smaller particles having the larger amount of surface in proportion to the mass, will have the larger proportion of nicotine material relative to the mass.

Furthermore, that form of the invention in which the dust is coated" with free nicotine is particularly efiective as a dust insecticide, and constitutes a new product.

The present process of making a' dust insecticide comprises the step of applying the nicotine as a vapor of free nicotine, which condenses on the surface of the carrier particles to form a substantially uniformlydistributed coating.

Y Where it is desired to provide the carrier particles with a coating of a nicotine salt, the product made as above mentioned and comprising a dust of particles coated with plained hereinafter in connection with the accompanying drawings, in which,-

Fig. 1 is a iagrammatic view of one' form of apparatus embodying the invention;

Fig. 2 is a detail view of'a modificatio: In carrying out my new process I first prepare a suitable pulverulent carrier which will not enter into reaction with free nicotine. This carrier I term inert, although it may consist of material which, While not reactive with nicotine or 1ts compounds,nuay itself have some value as an insectlcrde, germicide or fungicide, as, forexample, would be the case if very finely powdered sulphur were used as a carrier. A very suitable inert carrier is air slaked lime of such a degree of fineness that it will all pass through a screen of 100 mesh to the inch. -However, in place of this other carrier materials may be employed, for example, kaolin, gypsum, hydrated lime, sulphur, arsenate of lead, calcium arsenate or copper sulphate. Furthermore, mixtures of various materials in finely powdered form, and such that they will mixture of a solution of a nicotine salt with a caustic alkali. This mixture is then heated to a temperature between about 350 and 450 F. and the vapor led into contact with the carrier dust, upon which it condenses.

By mixing 10 pounds of an aqueous solution, containing 40% by weight of nicotine sulphate, with 1.5 poun'ds ofw freshly made hydrate of lime and then subjecting the mixture to a temperature of about 400 to 55 0 F.,. the free nicotine, in vapor form, is dr1von off and is conducted into contact with the carrier material, which is agitated, for example, b tumbling or showering it in the presenceo the vapor, so that the vapor may readily reach the surfaces of the particles of the carrier material. As thecarrier material is maintained at a temperature below the boiling oint of the free nicotine, condensation ta es place and theparticles of the carrier material are provided with a coating of free nicotine. The dust thus produced should be kept in sealed'receptacles until used.

Such an insecticide having a coating of free nicotine in a suitable finely powdered carrier, is particularly efiicient as a dust.

. a nicotinesalt will be sufiiciently eflective 'undermany .circums ances. Therefore, a further develo ment of the invention consists in subjecting the above-described product to a further step whereby the free nicotine is converted into a salt. This may be done by subjecting terial, while agitatmg it, tothe action of the vapor of an acid. Any suitable acid vapors on a leg or standard which may i the floor, in which case the the nicotine coated mamay be used. I have found that va ors of HCl or of acetic acid are particular y suitable. The chloride of nicotine formed by the first mentioned acid is more durable. that is, less easily decomposed, than the acetate of nicotine formed by the acetic acid treatment.

. It is obvious that the process hereinbefore described may be' carried out with simple apparatus of various types, but for working on a commercial scale the apparatus shown in the drawings is particularly suitable. This comprises a rotary drum indicated at 1, which as usual has circumferential tracks 2 mounted on rollers, some of which are indicated at 3. The drum is rotated in any suitable manner, as, for example, by providing. the drum with a circumferential rack 4 engaged by a pinion 5 on a shaft 6 arranged to be driven in any suitable way, as, for

example, by a pulley or an electric motor,

.drum. To the outer face of the drum-head is secured an auxiliary drum serving as a retort or still for evolving the desired vapor of free nicotine. This auxiliary drum, indicated at 8, has its outer end entirely closed while its inner end has a central opening in register with the opening in the corresponding endof the main drum. The auxiliar drum constitutes a circular retort or stil and is secured to the end of the main drum in any' suitable way, as, for example, by bolts indicated at 9.

To permit the retort to be charged and emptied, it is provided with an opening in its circumference, which opening is closed by a screw-threaded plug, as shown at 10.

The retort is arranged to be heated in any suitable way. In the example illustrated, a blast torch is'provided as indicated at 11, this being arranged to burn-gas, driven in by airunder pressure in a well lmown way.

To conserve the heat, a hood or shield 12 surmounts the retort and torch, this hood being held stationary, but being movable so as to permit access to the retort when charging or discharging it. The hood may be carried be slid along gas and air pipes for-the blast torch may be flexible hose.

The end of the main drum opposite the retort may have a central opening closed by 40% solution of nicotine sulphate.

v torch again brought into action.

a screw-threaded plug, as indicated at 13. This plug may be removed when starting the apparatus, and the vapors of free nicotine given ofi' by the retort will tend to drive the air from the drum. As soon as the free nicotine vapors are detected emerging from this vent opening the plug 13 is replaced and the drum set in rotation.

The drum 1 is provided with a. lid, as indicated at 14, which may be removed when necessary to charge or discharge the drum.

- In carrying out the process with this apparatus, a charge of the'pulverulcnt or dustlike inert carrier, which should all be line enough to pass a screen of 100 mesh, is supplied to the drum 1. Then a sutlicient quan tity of a mixture of freshly hydrated lime and a solution of a nicotine salt, preferably a 40% solution of nicotine sulphate or chloride, is charged into the retort. The size of the retort is such that the proper charge will occupy only the lower part of the retort and will not overflow into the main drum. The blast torch is set in operation to heat. the retort, this torch being directed at the lower part of the retort. The plug 13 is removed for a short time to allow the air to be ejected from the'drum by the vapors entering the drum from the retort. As soon as any nicotine vapor is detected escaping from the opening, the plug 13 is replaced. Then the drum is set in rotation.

. In the apparatus I have employed heretofore the drum is about 40 inches in diameter and about the same size in length. It is usually charged with about 200 pounds of air slaked lime which has passed through a screen of 100 mesh to the inch. The charge for the retort consists of about 0.75 pounds of freshly hydrated lime and 5 pounds of a The blast lamp is turned off about 45 minutes after starting and the drum rotated for about 60 minutes, that is, for about 15 minutes after the torch is extinguished. This insures the condensation of practically all the free nicotine in the drum.

The dust-like insecticide made as above described, is removed from the drum and charged at once into tin cans, which are immediately closed air-tight.

When it is desired to carry out the process further to convert the coating of free nicotine into a coating of nicotine salt, .the

dust treated as above described need not be cleaned out. Then some suitable acid, as,

for example, some hydrochloric acid or some acetic acid may be introduced into the retort, which is then closed and the blast The drum is set in rotation, and the acid vapors evolved from the retort enter the drum and act on the material therein. which during the rotation is being lifted up and showered down through the vapors. Thereby the coating of tree nicotine on the carrier particles is converted into a coating of nicotine salt, according to the acid used in the retort.

15 is stationary and is connected to the drum by a pipe, 16 which has a-packed joint 17 where it joins the drum so that'the latter may rotate while the pipe 16 is stationary.

The still 15 is heated in any suitable way and has an opening with a closure 18 Whereby it may be charged and emptied.

What I claim is: 1. A dust insecticide material comprising inert material of different sized particles coated with a nicotine insecticide, said dust insecticide material showing a higher percentage by weight. of nicotine on the finer particles than on the coarser particles, substantially as described. 1

2. A dust insecticide material comprising particles of inert material coated with free nicotine.

3. A dust insecticide material comprising inert material of different sized particles coated with tree nicotine. said dust insecticide material showing a. higher percentage by weight of free nicotine on the finer particles than on the coarser particles, substantially as described.

4. The-process of making a dust insecticide material containing a nicotine insect-i cide, which consists in subjecting finely pulverulent material to the action of a vapor containing free nicotine while maintaining the pulvcrulent material cool enough to condense said vapor.

' 5. The process of making a dust insecticide material, which consists in making a mixture of hydrated lime and a, solution of a nicotine salt, subjecting said mixture to heat suflicient to vaporize the free nicotine. and contacting the evolved vapors from the mixture with'a dust-like carrier material inert to the nicotine.

6. The process of making a dust insecticide material, which consists in making a mixture of hydrated lime and a solution of a nicotine salt, subjecting said mixture to heat sufficient to vaporize the free nicotine. and leading the vapors evolved from the mixture into contact with a dust-like carrier material inert to the nicotine while agitating said carrier material.

7. The process of making a dust insecticide material containing a nicotine insecticide, which consists in subjecting finely pulthe free nicotine isconverted into the cor-v responding nicotine salt.

8. The process of making a dust insecticide material containing a nicotine insecticide, which consists in producing a vapor containing free nicotine, leading said vapor into contact with a dust-like carrier material inert to the nicotine while agitating said carrier material, then producing an acid vapor, and leading said acid vapor into contact with the carrier material carrying the free nicotine, while agitating said carrier material.

9. In an apparatus for making dust insecticide material carrying a mcotine insecticide, the combinatlon with means for agitating a carrier material in dust form, of means for evolving free nicotine vapor, and means for conducting said vapor into contact with the carrier material while the same is being agitated.

10. In an apparatus for making dust insecticide material carrying a nicotine insecticide the combination with a rotatable drum containing means for lifting and showering a pulverulent carrier material, of a retort in communication with the interior of the drum, and means for heatin said retort.

In testimony whereof, I have ereunto set my hand.

HENRY K. MCCONNELL. 

